Switch



Feb. 9, 1937. B. DURHAM SWITCH Filed Jan. 30, 1935 3 Sheets-Sheet l Feb.9, 1937. B, A. DURHAM 2,069,946

SWITCH Filed Jan. 30, 1935 3 Sheets-Sheet 2 jaw??? 09 mw/gmzwz Feb. 9,1937. DURHAM 2,069,946

SWITCH Filed Jan. 30, 1955 5 Sheet-Sheet s Patented Feb. 9, 1937 UNITEDSTATES PATENT OFFICE 15 Claims.

This invention relates to new and useful improvements in switches andhas for its primary object to provide a device of this character whichis compact, easily installed, practically fool-proof and cheap. Furtherobjects of my invention are to provide a device of this character whichplaces all electrical circuits under one control and the elimination offire hazards due to short-circuits.

In carrying out my invention it is my purpose to provide a master switchof the type hereinafter described which will automatically become lockedwhen the operating circuits have been switched off and the motor hasbeen brought to a stop, necessitating the employment of a key providedfor the purpose, before the motorcan again be started or the vehicleagain set in motion under its' own power. It is also my purpose toprevent electrical circuits or currents being by-passed around themaster switch without first having passed through the primarycontrolling element of the operating circuit of the master switch,thereby-forestalling the en loyment of jumpers or other devices ormethods, or of any manipulation whatsoever of any circuits outside themaster switch in an unlawful effort to start a motor vehicle which hasbeen locked automatically with the stopping of the motor.

In my device the primary controlling element of the operating circuit isof the cut-out or circult breaker type and is constructed to operateonly when the electrical system has become grounded or short-circuitedbecause of a defect in the system or because of any other natural orunnatural condition which may exist outside the master switch. When themaster switch is set in the off position and therefore automaticallylocked it will, when activated by a ground or short-circuit or othernatural or unnatural condition, open the operating primary circuitthereby causing all circuits in the operating circuit to becomeinoperative or dead.

When the primary controlling element has thu been brought into actionand the primary circuit has been caused to open, such opening closes thetell-tale lamp circuit and lights the tell-tale lamp which is locatedinside the master switch. This lamp, of any attention-arrestingc0lor,'is visible on the face of the master switch and, when lighted,indicates trouble or an unnatural condition existing in the electricalsystem.

In my device there can be but one cause for the operation of thecontrolling element in the primary operating circuit, viz: a groundcircuit must be provided between the negative post of the battery andthe chassis (the common ground) which circuit is open when the mechanismof the master switch is set in the off position and therefore locked. Toclear the controlling element and the tell-tale lamp the master switchmust be unlocked and the master control lever must be advanced to therunning position, thus releasing the locking device of the primarycontrolling element and permitting the same to return to its normalposition. If however, upon returning the master control lever to the 01!position where it again becomes locked," the primary controlling elementagain operates and the tell-tale lamp lights, trouble is indicated asbeing still present. This trouble must be located and removed before themotor vehicle can again be started or operated.

With these and other objectives in view, the invention consists of theconstruction, combination and arrangement of the parts and circuitshereinafter described and detailed in the accompanying drawings, inwhich:

Figure 1 is a plan view thereof.

Figure 2 is a transverse horizontal section therethrough.

Figure 3 is a vertical section of Figure 2.

Figure 4 is a similar section of Figure 2 taken at right angles toFigure 3.

Figure 5 is a fragmentary section showing the fuse plug attachment.

Figure 6 and Figure 7 are detail views of the coil members.

Figure 8 is a view of my device mounted on a panel board.

Figures 9, 10 and 11 are wiring di rams showing the method of hooking upmy device.

Beginning at the battery a cable is connected between the plus positivepost of the battery and the terminal I of the master switch. From thispoint the circuit is continued through the contact 2 and is connected tothe contact plate 4 by means of the contact shoe 5 which bridges theneutral space 3. The contact shoe 5 and the contact shoe arm I areinsulated from the main rotor body 8 with an accepted insulatingmaterial 9 as shown in the cross sectioned view. A cable from theterminal 6 of the contact plate 4 is connected to the starting motorthus completing the positive side of the starting circuit.

The negative side of the battery circuit, known as the common ground, isreturned through the chassis and other metal conductors to the masterswitch body or shell Ill. The mounting plate ll, upon which is mountedthe lock barrel I2 is carried upon the lugs.l3 in the shell Ill. Thecontact arms 7 and [4 are of spring metal and when mounted, exert anupward thrust on the rotor 8 and against the top plate l5. The contactarm l4 and the contact shoe I! are not insulated, but

circuit is the same as that employed in the starting circuit.

Beginning at the terminal 20 the wire circuit 2| is carried through theinsulating panel and support plate at 22 to the terminal 23 of thecircuit-breakem' through the breaker contact points 24 to the terminal25, then back through wire 26, the opening 22 in the insulating .panelto the opening in the shell Ill, and thence to the ammeter and generatorof any assembly which the various motor vehicle manufacturers nowemploy, or in the future may design.

Therefore, when the rotor 8 is set in the "oif position and is looked asshown, the contact shoe I1 is removed from the contact plate l8, therebyopening the ground circuit between the rotor 8 and the contact plate l8thus rendering inoperative or dead all circuits except the parking andtail-light circuits.

When the rotor 8 is in the off position, the primary circuit-breaker isactivated by the contact arm I on the contact shoe 5 which is in contactat all times with the contact plate 2. From the contact arm I, theactivating circuit of the primary circuit-breaker continues through theterminal 28 of the contact arm I to the terminal 29 and through contactpoints 30 to the terminal 3|, thence to the breaker coil winding 32. Theother end of the coil winding is grounded.

When the control rotor 8 is in the off position and the ground circuitto the battery is open, the onlymethod of actuating the circuit breakeris to establish a ground connection between the battery terminal at thebattery and the chassis or frame. When such a ground is establishedoutside the master switch, the operating circuitbreaker is brought intoaction. The activity is as follows:

. The coil of the circuit-breaker having been actuated because of theground circuit having been closed by an electrical connection madeoutside the master switch the coil armature 33 is drawndownward thusopening the contact points in both the operating and breaker circuits.The armature is locked in this position by the armature lock 34 thusrendering the entire operating system dead, parking and tail-lightsincluded.

When the coil armature has been drawn downward and looked as abovedescribed the contact points 35 are closed causing a circuit to flowthrough the terminal 36 and wire 3! to the lamp terminal 38. The currentpasses through the lamp 39 to the lamp terminal 40, thence by wire 4|through the opening 22 in the insulating panel, to the terminal 42 ofthe negative battery contact plate l8, causing the tell-tale lamp tolight, same being visible on the front of the master switch andindicating a ground in the system.

To clear the circuit-breaker in the master switch, themaster switch-keymust be employed.

After the switch is unlocked the master control ,is'set in the runningposition, thus causing the boss 43 (which is part of the rotor 8) topass over and release the armature lock 34, thereby allowing thearmature 33 to return to its normal position. If, however, uponreturning the master control lever to the o position, thecircuit-breaker should again operate, a ground outside the master switchis indicated and such ground must be removed before the motor vehiclecan again be operated under its own power.

The parking and tail-light circuits (which are of the two-wire system)are operated in the usual way, that is, from the lighting switch. Thelamps are of the double-contact type and the negative circuit isreturned to the master switch through wires 44 and 45 instead of throughthe chassis or common ground; through the insulator 46, to the terminal41 on the fuse block 48, thence through the fuse 49 as shown in Fig. 3,to the terminal 50, thence to the terminal 42 of the negative contactplate l8.

There is no possibility of a ground in the parking or tail-lightcircuits as the negative or common ground circuit to the battery is openwhen the master control is set in the off position There is, however, apossibility of a direct shortcircuit between the positive and negativecircuits of the parking and tail-lamps at the lamp connections, or bythe two circuits becoming bared or otherwise united, a condition whichis present in any two-wire system. To eliminate possibility of fire atthis source, a fuse block and fuse is placed in the ground circuit. Thisfuse is readily accessible, being fixed on the back of the master switchas shown in Fig. 3.

Should any short-circuit occur, the high amperage flowing to the groundwould instantly melt the fuse and open the negative circuits of theparking and tail-lights, thus rendering these circuits inoperative andabsolutely free of all electrical energy, there being no other groundthrough which to complete the circuit.

I have described my invention as applied to automobiles, but it is welladapted to aeroplane. lighte'r-than-ain craft, and submarines, or anyother device wherein a switch of this character may be employed, and theclaims should be interpreted accordingly.

What I claim is:

1. In an electrical system for automotive mechanism includingstarter,ignition, generator and lighting circuits a control device for saidcircuits comprising a. first contact having'a wire connection to astarting motor, 'a' second contact having a wire connection to a .loadand to a first battery terminal, a third contact, a fourth contacthaving a wire connection to a second battery terminal, a circuit-breakercoil having a wire connection to the third contact, a switch for theload circuit adapted to be operated by the coil, 9. switch for the coilcircuit adapted to be operated by the coil, means for holding saidswitches in open position, an insulated movable switch member forconnecting the starting motor and circuit-breaker coil to the firstbattery terminal contact, and a grounded movable switch member forconnecting the second battery terminal contact to ground, said switchmembers being movable successively to close the motor start r circuit,to close the load circuit, and to close the circuit-breaker coil circuitwhile opening the battery switch. V

2. In an electrical system for automotive mechanism including starter,ignition, generator-and 75 lighting circuits, a control device for saidcircuits. comprising a first contact having a wire connection to astarting motor, a second contact having a wire connection to a load andto a first battery terminal, a third contact, a fourth contact having awire connection to a second battery terminal, a circuit-breaker coilhaving a wire connection to the third contact, a switch for the loadcircuit adapted to be operated by the coil, a switch for the coilcircuit adapted to be operated by .the coil, means for holding saidswitches in open position, an insulated movable switch member forconnecting the starting motor and circuit-breaker coil to the firstbattery terminal contact, a grounded movable switch member forconnecting the second battery terminal contact to ground, said switchmembers being movable successively to close the motor starter circuit,to close the load circuit, and to close the circuitbreaker coil circuitwhile opening the battery switch, and means for-releasing the holdingmeans oi. said switches.

3. In an electrical system for automotive mechanism including starter,ignition, generator and lighting circuits, a control device for saidcircuits comprising a first contact having a wire connection to astarting motor, a second contact having a wire connection to a load andto a first battery terminal, a third contact,'a fourth contact having awire connection to a second battery terminal, a circuit-breaker coilhaving a wire connection to the third contact, a switch for the loadcircuit adapted to be operated by the coil, a switch for the coilcircuit adapted to be operated by the coil, means for holding saidswitches in open position, an insulated movable switch member forconnecting the starting motor and circuit-breaker coil to the firstbattery terminal contact, a grounded movable switch member forconnecting the second battery terminal contact to ground, said switchmembers being movable successively to close the motor starter circuit,to close the load circuit, and to close the circuit-breaker coil circuitwhile opening the battery switch, means for releasing the holding meansof said switches, and means for indicating the formation of a by-passcircuit for the second battery terminal contact.

4. In an electrical system for automotive mechanism including a load andbattery, a control device comprising a first contact having a wireconnection to a load and to a first battery terminal, a second contact,a third contact having a wire connection to a second battery terminal, acircuit-breaker coil having a wire connection to the second contact, aswitch for the load circuit adapted to be operated by the coil, a switchfor the coil circuit adapted to be operated by the coil, means forholding said switches in open position, an insulated movable switchmember for connecting the circuit-breaker coil to the first batteryterminal contact, a grounded movable switch member for connecting thesecond terminal battery contact to ground, said switch members beingmovable successively to close the load circuit and to close thecircuit-breaker coil circuit while opening the battery circuit.

5. In an electrical system for automotive mechanism including a load andbattery, a control device comprising a first contact having a wireconnection to a load and to a first battery terminal, a second contact,a third contact having a wire connection to a second battery terminal, acircuit-breaker coil having a wire connection to the second contact, aswitch for the load circuit adapted to be operated by the coil, a switchfor the 'coil circuit adapted to be operated by the coil, means forholding said switches in open position, an insulated movable switchmember for connecting the circuit-breaker coil to the first batteryterminal contact, a grounded movable switch member for connecting thesecond terminal battery contact to ground, said switch members beingmovable successively to close the load circuit and to close thecircuitbreaker coil circuit while opening the battery circuit, and meansfor releasing the holding means of said switches.

6. In an electrical system for automotive mechanism including a load andbattery, a control device comprising a first contact having a wireconnection to a load and to a first battery terminal, a second contact,a third contact having a wire connection to a second battery terminal, acircuit-breaker coil having a wire connection to the second contact, aswitch' for the --load circuit adapted to be operated by the coil, aswitch for the coil circuit adapted to be operated by the coil, meansfor holding said switches in open position, an insulated movable switchmember for connecting the circuit-breaker coil to the first batteryterminal contact, a grounded movable switch member for connecting thesecond terminal battery contact to ground, said switch members beingmovable successively to close the load circuit and to close thecircuit-breaker coil circuit while opening the battery circuit, meansfor releasing the holding means of said switches.

and means for indicating the formation of a bypass circuit for thesecond battery terminal contact.

7. In an electrical system for automotive mechanism including a load andbattery, a control device comprising a first contact having a wireconnection to a load and to a first battery terminal, a second contact,a third contact having a wire connection to a second battery terminal,an insulatedmovable switch member for connecting a circuit-breaker coilto the first battery terminal contact, a grounded movable switch memberfor connecting the second battery terminal to ground, and meansincluding said circuit-breaker coil for breaking said-load connectionwhen the insulated switch member engages with the second contact whenthe grounded switch opens the ground circuit and when a by-pass isformed about said third contact.

8. In an electrical system for automotive mechanism including a load andbattery, a control device comprising a first contact having a wireconnection'to a load and to a first battery terminal, a second contact,a third contact having a wire connection to a second battery terminal,an insulated movable switch member for connecting the circuit=breakercoil to the first battery terminal contact, a grounded movable switchmember for connecting the second battery terminal to ground, means forbreaking said load connection when the insulated switch member engageswith the second contact when the grounded switch opens the groundcircuit and when a bypass is formed about said third contact, and meansfor indicating a by-pass of said third contact.

9. A contact having a permanent wire connection to a first batteryterminal and a wire connection to ground, an insulated contact having apermanent wire connection to a second battery terminal, a groundedswitch member movable to ground said insulated contact, and means for.10 means for holding said ground wire connections opening said groundwire connection when the insulated contact is electrically shunted.

10. A contact having a permanent wire connection to a first batteryterminal and a wire connection to ground, an insulated contact having apermanent wire connection to a second battery terminal, a groundedswitch member movable to ground said insulated contact, means foropening said ground wire. connection when the insulated contact iselectrically shunted, and

connection to ground, an insulated contact having a permanent wireconnection to a second battery terminal, a grounded switch membermovable to ground said insulated contact, means for opening said groundwire connection when the insulated contact is electrically shunted. andsignalling means for indicating formation of said shunt.

13. In combination, a battery, an electric gen erator, a load, a switchunit comprising a contact having a permanent wire connection to a firstbattery terminal and a wire connection to ground, an insulated contacthaving a permanent wire connection to a second battery terminal, and agrounded switch member movable to ground said insulated contact, meansfor open-. ing said ground wire connection when the insulated contact iselectrically shunted, means for holding said ground wire connectionsopen, additional means for disabling said ground wire connection openingmeans, and signalling means for indicating formation of said shunt.

14. An electrical system for internal combustion engines comprising astarting motor, battery and load, a master switch including first,second, third and fourth contacts, an insulated movable switch memberfor connecting said first and second contacts, and a grounded switchmember for grounding the third contact, a circuit connecting the firstcontact and the motor, a circuit connecting the load and second contact,a circuit connecting a first battery terminal to the second contact, acircuit connecting a second battery terminal to the third contact, asecond switch in said load circuit, electromagnetic means for operatingthe second switch, a circuit between the electromagnetic means and thefourth contact, said insulated switch member being adapted to close thesecond and fourth contacts when said grounded member is disconnectedfrom the third contact.

15. An electrical system for internal combustion engines comprising astarting motor, battery, load, a master switch, said switch includingfirst, second, third and fourth contacts, an insulated movable switchmember for connecting the first and second contacts and a groundedswitch member for grounding the third contact, a circuit connecting thefirst contact and motor, a circuit connecting the load and secondcontact, a circuit connecting a first battery terminal to the secondcontact, a circuit connecting a second battery terminal to the thirdcontact, a second switch in said load circuit, electromagnetic means foroperating said second switch, and a circuit between the electromagneticswitch and said fourth contact, said insulated switch member beingadapted to close the second and fourth contacts when said groundedmember is disconnected from the third contact, said electromagneticmeans being energized only when said second battery terminal isgrounded.

BALTIS ARTHUR DURHAM.

